Implantable lead assembly

ABSTRACT

An implantable lead assembly is provided that comprises a lead body having a proximal end portion and a distal end portion, and having a length extending there between. A plurality of electrodes are disposed along the lead body. A plurality of cable conductors are contained within the lead body, the conductors extending from the electrodes to the proximal end portion. A lead connector is provided at the proximal end portion. The lead connector includes a connector pin configured to mate with a corresponding header contact; a first termination pin coupled to one of the plurality of cable conductors; a collar coupler securely and electrically coupling the connector pin and first termination pin in an axially offset alignment with one another; and a body segment that is elongated along a longitudinal axis and extends between a header mating face and a lead mating end. The body segment is over-molded about the connector pin, the first termination pin and the collar coupler, the connector pin extending from the header mating face, the first termination pin extending from the lead mating end.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/681,985, filed Apr. 8, 2015.

FIELD OF THE INVENTION

Embodiments herein generally relate to implantable lead assemblies, andmore particularly to implantable lead assemblies having an over-moldedconnector assembly.

BACKGROUND OF THE INVENTION

A body implantable lead assembly forms an electrical connection betweena patient's anatomy and a pulse generator such as a cardiac pacemaker,an implantable cardioverter defibrillator (ICD), an appetite or painsuppression device, and the like. The lead assembly includes a lead bodycomprising a tubular, flexible biocompatible, biostable insulativesheath or housing, such as formed of silicone rubber, polyurethane orother suitable polymer. One example of a lead body is a lead having atip electrode, a ring electrode and one or more other electrodesdisposed along the lead body. In many configurations, the lead includesa coaxial conductor extending about a central lumen of the lead body.Another example of a lead body is a cardioverter/defibrillator lead thatincludes a sensing ring, a shocking right ventricle (RV) electrode, ashocking superior vena cava (SVC) electrode and a tip sensing/pacingelectrode. The lead includes a multi-lumen housing, each lumen of whichcarries a separate conductor through the lead housing to each of thesensing ring, RV electrode, SVC electrode and tip electrode.

In certain applications, coil conductors may be used, while in otherapplications single or multi-strand cable conductors may be used toconnect the pulse generator at the proximal end portion of the lead withthe corresponding electrodes at the distal end portion of the lead. Insome existing multi-lumen lead bodies, a combination of a coil conductorand one or more cable conductors may be utilized.

To facilitate connection of an implantable lead to a compatible pulsegenerator, the proximal lead connector is inserted and secured in thedevice header. This provides the mechanical and electrical connectionbetween the implantable lead and the device. For the current generationcardiac leads, the design includes a connector pin which is terminatedto an inner coil conductor by welding and/or crimping. The coilconductor extends from the connector to the distal tip of the lead.

Current generation IS4/DF4 leads utilize a coil conductor (extendingabout the core lumen) to connect the tip electrode to the connector pinand utilize cables to make additional terminations. Termination crimpsleeves are attached to the proximal end of each conductor cable. Thetermination crimp sleeves are welded to termination pins on the distalend of conventional IS4/DF4 connectors to provide an electrical andmechanical connection. The IS4/DF4 connectors have three distaltermination pins to facilitate connection with three termination crimpsleeves and cable assemblies. The IS4/DF4 leads utilize an innerconductive coil to provide an electrical connection from the connectorpin to the lead tip electrode. In active fixation leads, the conductivecoil is also used to provide torque through rotation of the connectorpin to extend and retract the helix fixation mechanism. In passivefixation leads, the conductive coil acts as an electrical conductor andas a pathway for delivery tools (such as guidewires and stylets).

However, existing connector assemblies used with the above noted leadconfigurations experience certain limitations. For example, theconnector pin, which is rotatably located in a header mating face of theconnector assembly, exhibits a certain amount of axial movement Theaxial movement of the connector pin affects the position of theconnector within the header which changes the relative alignment betweencontacts on the connector assembly relative to mating contacts in theheader. The axial movement of the connector pin limits manufacturingtolerances associated with other contacts on the connector assembly.

A need remains for a connector assembly for a lead body comprisingmultiple cable conductors wound in a spiral manner about the lead bodywithout an inner coil conductor to provide select characteristics inlead delivery and lead body durability.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with at least one embodiment, an implantable lead assemblyis provided that comprises a lead body having a proximal end portion anda distal end portion, and having a length extending there between. Aplurality of electrodes are disposed along the lead body. A plurality ofcable conductors are contained within the lead body, the conductorsextending from the electrodes to the proximal end portion. A leadconnector is provided at the proximal end portion. The lead connectorincludes a connector pin configured to mate with a corresponding headercontact; a first termination pin coupled to one of the plurality ofcable conductors; a collar coupler securely and electrically couplingthe connector pin and first termination pin in an axially offsetalignment with one another; and a body segment that is elongated along alongitudinal axis and extends between a header mating face and a leadmating end. The body segment is over-molded about the connector pin, thefirst termination pin and the collar coupler, the connector pinextending from the header mating face, the first termination pinextending from the lead mating end.

Optionally, the connector pin may be aligned with and extend along thelongitudinal axis of the body segment and the first termination pin maybe offset radially from the longitudinal axis. The first termination pinis electrically coupled to one of the cable conductors. The cableconductors wind in a spiral manner about a length of the lead body.Optionally, the lead assembly further comprises a second termination pinconnected to a ring contact, where the second termination pin extendsfrom the lead mating end. A ring contact extends about an exterior ofthe body segment at a predetermined position along the body segmentspaced relative to the connector pin.

Optionally, a plurality of termination pins extend from the lead matingend. Optionally, the plurality of termination pins include the firsttermination pin, where the plurality of termination pins extend in acommon direction as the longitudinal axis, and the plurality oftermination pins are radially distributed outward from the longitudinalaxis in a circumferential arrangement about the lead mating end. Theconnector pin may include a base section that is rigidly secured duringmolding within the body segment and includes an interconnect sectionthat extends from the header mating face. The connector pin includes aninner end that is over-molded within the body segment, the inner endbeing physically separated from the conductors. Optionally, the bodysegment includes a lead interconnect region at the lead mating end, thelead interconnect region having a fluted cross-section to form crimppockets, the conductors being joined through crimp sleeves tocorresponding termination pins in the crimp pockets.

Optionally, the body segment further comprises a support arm and corepost projecting from lead mating end and centered along the longitudinalaxis, the core post including a flared barb, the core post and barbshaped and dimensioned to be frictionally secured within a core lumenwithin a proximal end portion of the lead body.

In accordance with at least one embodiment, a method of manufacturing alead assembly comprises providing a lead connector by: coupling aconnector pin to a first termination pin through a collar coupler suchthat the connector pin and first termination pin are in an axiallyoffset alignment with one another; and over molding a body segment aboutthe connector pin, the first termination pin and the collar coupler, thebody segment being elongated along a longitudinal axis and extendingbetween a header mating face and a lead mating end, the connector pinpositioned along the longitudinal axis and extending from the headermating face, the first termination pin positioned axially offset fromthe longitudinal axis and extending from the lead mating end. The methodincludes attaching the lead connector to a proximal end portion of alead body having a plurality of electrodes disposed along the lead body,the lead body including a plurality of cable conductors; and joining thefirst termination pin to a proximal end of a first conductor from theplurality of cable conductors.

In accordance with at least one embodiment, the method further comprisesaffixing the connector pin within the body segment in a non-rotationalmanner, and electrically coupling the connector pin to the firstconductor by attaching the first conductor to the first termination pinthrough a crimp sleeve, the cable conductors winding in a spiral mannerabout a length of the lead body.

In accordance with at least one embodiment, the method further comprisescoupling a plurality of termination pins to ring contacts; loading theplurality of termination pins, the ring contacts, the first terminationpin, and the connector pin into an injection mold; and over molding theplurality of termination pins, the ring contacts, the first terminationpin, and the connector pin such that the plurality of termination pinsproject from the lead mating end and the ring contacts extendcircumferentially about an exterior of the body segment at predeterminedpositions spaced along the body segment.

In accordance with at least one embodiment, the method further comprisesspacing the ring contacts along a length of the body segment by aspacing relative to the header mating face of the body segment.Optionally, the plurality of termination pins and the first terminationpin extend in a common direction as the longitudinal axis and areradially distributed outward from the longitudinal axis in acircumferential arrangement about the lead mating end. Optionally, theconnector pin includes a base section that is tapered along a lengththereof and is rigidly secured during molding within the body segment.The body segment includes a lead interconnect region extending from thelead mating end, the lead interconnect region having a flutedcross-section to form crimp pockets, the conductors being joined throughcrimp sleeves to corresponding termination pins in the crimp pockets.The body segment may further comprise a support arm and core postprojecting from lead mating end and centered along the longitudinalaxis, the core post including a flared barb, the core post and barbshaped and dimensioned to be frictionally secured within a core lumenwithin a proximal end portion of the lead body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an implantable medical device and external device,coupled to a heart in accordance with an embodiment herein.

FIG. 1B illustrates a lead assembly formed in accordance with anembodiment herein.

FIG. 2A illustrates a side view of the connector assembly of FIG. 1Bformed in accordance with an embodiment herein.

FIG. 2B illustrates an end perspective view of a lead interconnectregion formed in accordance with an embodiment herein.

FIG. 2C illustrates an end view of the connector assembly from the leadmating end formed in accordance with an embodiment herein.

FIG. 2D illustrates a sectional view taken along line 2D-2D in FIG. 2Cthrough the connector assembly.

FIG. 2E illustrates a sectional view taken along line 2E-2E in FIG. 2Cthrough the connector assembly.

FIG. 3A illustrates a perspective view of the interconnection areabetween the connector pin and the corresponding termination pin formedin accordance with an embodiment herein.

FIG. 3B illustrates a perspective view of an interconnection regionbetween the connector pin and the corresponding termination pin formedin accordance with an embodiment herein.

FIG. 4 illustrates a flowchart for a method of manufacture for a leadassembly in accordance with embodiments herein.

FIG. 5 illustrates proximal ends of the conductors when loaded intocrimping sleeves that are then loaded over the termination pins inaccordance with an embodiment herein.

FIG. 6 illustrates an end view of the connector assembly from the leadmating end after the crimping sleeves have been installed to secure theconductors to the termination pins in accordance with an embodimentherein.

FIG. 7 illustrates a side perspective view of the lead mating end of theconnector assembly and the proximal portion of the lead body inaccordance with an embodiment herein.

FIG. 8 illustrates the components as loaded in a mold in accordance withan embodiment herein.

DETAILED DESCRIPTION OF THE INVENTION

The following description presents embodiments herein. This descriptionis not to be taken in a limiting sense but is made merely for thepurpose of describing the general principles of the embodiments whosescope is defined by the appended claims. Although the followingembodiments are described principally in the context ofcardioverting/defibrillating connector/leads, the present disclosure maybe applied to other connector/lead structures. For example, embodimentsmay be used with devices that suppress an individual's appetite, reduceor offset pain associated with chronic conditions and control motorskills for handicap individuals.

Embodiments herein allow for the design and fabrication of a cardiaclead with multiple conductors within the lead body (e.g., four or more).For example, an IS4 connector assembly is provided herein with four-pintermination hardware and a fluted geometry that allows for theconnection of four termination crimp sleeves and cable conductors.Embodiments herein enable the use of a lead with a lead bodyconstruction that avoids the use of an inner coil conductor, therebyallowing for select delivery tool interaction and lead body durability.The connector pin is over-molded to prevent rotation (e.g., inconnection with a passive fixation lead). By over-molding the connectorpin, embodiments herein eliminate axial and radial pin movement, therebyreducing the number of components and manufacturing process steps. Toimprove lead manufacturability, a feature is present on the distal endof the connector assembly to provide stability during assembly andafford a seal to prevent medical adhesive leakage during backfillingoperations. As one example, the connector assembly may be an IS4compatible lead connector, although numerous other embodiments may beimplemented.

FIG. 1A illustrates an IMD 100 and external device 600 coupled to aheart 102 in a patient and implemented in accordance with oneembodiment. The external device 600 may be a programmer, an externaldefibrillator, a workstation, a portable computer, a personal digitalassistant, a cell phone and the like. The IMD 100 may be a cardiacpacemaker, an ICD, a defibrillator, an ICD coupled with a pacemaker, andthe like. The IMD 100 may be a dual-chamber stimulation device capableof treating both fast and slow arrhythmias with stimulation therapy,including cardioversion, defibrillation, and pacing stimulation, as wellas capable of detecting heart failure, evaluating its severity, trackingthe progression thereof, and controlling the delivery of therapy andwarnings in response thereto. The IMD 100 may be controlled to senseatrial and ventricular waveforms of interest, discriminate between twoor more ventricular waveforms of interest, deliver stimulus pulses orshocks, and inhibit application of a stimulation pulse to a heart basedon the discrimination between the waveforms of interest and the like.

The IMD 100 includes a housing 104 that is joined to a header assembly106 that receives connectors 108, 110, 112 connected to a rightventricular lead 114, a right atrial lead 116, and a coronary sinus lead118, respectively. The leads 114, 116, and 118 measure cardiac signalsof the heart 102. The right atrial lead 116 includes an atrial tipelectrode 120 and an atrial ring electrode 122. The coronary sinus lead118 includes a left ventricular tip electrode 124, a left atrial ringelectrode 126, and a left atrial coil electrode 128. The coronary sinuslead 118 also includes an LV ring electrode 130 disposed between the LVtip electrode 124 and the left atrial ring electrode 126. The rightventricular lead 114 has an RV tip electrode 136, an RV ring electrode132, an RV coil electrode 134, and an SVC coil electrode 138. The leads114, 116, and 118 detect IEGM signals that form an electrical activityindicator of myocardial function over multiple cardiac cycles.

During implantation, the external device 600 may be connected to one ormore of the leads 114, 116, 118 through temporary inputs 603. The inputs603 of the external device 600 receive IEGM signals from the leads 114,116, 118 during implantation and displays the IEGM signals to thephysician on display 622. Optionally, the external device 600 may not bedirectly connected to the leads 114, 116 and 118. Instead, the IEGMcardiac signals sensed by the leads 114, 116 and 118 may be collected bythe IMD 100 and then transmitted wirelessly to the external device 600.Hence, the external device 600 receives the IEGM cardiac signals throughtelemetry circuit inputs. The physician or another user controlsoperation of the external device 600 through a user interface 601.

FIG. 1B illustrates the lead assembly 118 formed in accordance with anembodiment herein. The lead assembly 118 includes a lead body 12 havinga distal end portion 14 and a proximal end portion 16. The lead body 12has a length that extends along a longitudinal axis 13 between thedistal and proximal end portions 14 and 16. The term longitudinal axisencompasses both linear and non-linear axes. The longitudinal axis 13 ofthe lead body 12 extends along a curved path that changes as the leadbody is flexed, bent and otherwise manipulated. The lead assembly 10includes a plurality of electrodes 21-24 that may be constructed as tip,coil and/or ring electrodes. The electrodes 21-24 are spaced apart fromone another along the lead body, such as proximate to the distal endportion 14. A plurality of conductors (not shown in FIG. 1B) arecontained within the lead body 12. The conductors extend from theelectrodes 21-25 to the proximal end portion 16. The lead body 12includes an insulating sheath or housing of a suitable insulative,biocompatible, biostable material such as, for example, silicone rubberor polyurethane, extending substantially the entire length of the leadbody and surrounding the conductors. Various combinations of theelectrodes 21-24 are used in connection with sensing cardiac signalsand/or delivering stimulation therapies.

The proximal end portion 16 is joined to a connector assembly 50 that isconfigured to couple the lead assembly 118 to an IMD 100, externaldevice 600 or other device. The connector assembly 50 comprises one ormore connectors that may conform to the DF-1 standard when used forsupplying electrical impulses for defibrillation, and/or may conform tothe IS-1 standard when connecting a pacemaker/defibrillator to theelectrodes 21-24.

FIG. 2A illustrates a side view of the connector assembly 50 of FIG. 1B.The connector assembly 50 includes a body segment 52 that is elongated,such as shaped in a tubular cross section or other cross section shapedto fit in a header receptacle. The body segment 52 is elongated along alongitudinal axis 58. The body segment 52 includes a header mating face54 and a lead mating end 56. The header mating face 54 is loaded firstinto a receptacle in the header during an implant procedure. The bodysegment 52 is over-molded about various components, a portion of whichare visible in FIG. 2. A connector pin 80 extends from the header matingface 54, while a plurality of termination pins 73-76 extend from thelead mating end 56. As explained herein, the body segment is over-moldedabout interior portions of the connector pin 80 and termination pins73-76. Among other things, the over molding process reducesmanufacturing steps, eliminates axial movement of the pins and providesa rigid interconnection between the various components, therebymaintaining predetermined tolerances and spacing between the componentswithin the connector assembly 50. The connector pin 80 is fixed in anon-rotational position within the body segment.

The connector assembly 50 includes a plurality of ring contacts 64-66that are spaced in an axially distributed manner along a length of thebody segment 52. The ring contacts 64-66 are securely formed with thebody segment 52 during the over molding process. The ring contacts 64-66are separated from on another by seal zones 60-63 which representportions of the body segment 52. The seal zones 60-63 facilitateelectrical and physical separation and isolation between the ringcontacts 64-66 and ensure no two ring contacts 64-65 engage a singlecontact within the header receptacle. In accordance with at least someembodiments, by securing the ring contacts 64-66 to the body segment 52during the over molding process, a predetermined spacing is maintained,with a very small or narrow tolerance, for the ring contacts 64-66relative to the connector pin 80. For example, predetermined spacings81-83 may be defined as corresponding distances between the headermating face 54 of the body segment 52 and leading edges of thecorresponding ring contacts 64-66. The spacings 81-83 are set such thateach ring contact 64-66 will be aligned with an individual correspondingheader contact within the receptacle of the header when the headermating face 54 of the body segment 52 engages or bottoms out with aninterior wall of the header receptacle.

Once the over molding process is complete, the connector pin 80 and ringcontacts 64-66 are held rigidly relative to one another in a manner thateliminates axial movement and that eliminates rotation (non-rotationalrelation). The ring contacts 64-66 extend about an exterior of the bodysegment 52 at predetermined positions along the body segment 52 andspaced a desired distance relative to the connector pin 80.

The body segment 52 also includes a lead interconnect region 68configured to be received within and securely attached to the proximalend portion 16 of the lead body 12. The lead interconnect region 68includes a support arm 77 and core post 78 that are formed integral withthe body segment 52 and extend along the longitudinal axis 58 from thelead mating end 56. The lead interconnect region 68 also includes aplurality of support posts 72 positioned about the support arm 77 andextending from the lead mating end 56. The support posts 72 extend aboutand provide added support for the termination pins 73-76. Thetermination pins 73-76 extend in a common direction as the longitudinalaxis 58 and are radially distributed outward from the longitudinal axis58 and evenly spaced in a circumferential arrangement about the leadmating end 56.

FIG. 2B illustrates an end perspective view of the lead interconnectregion 68 formed in accordance with an embodiment herein. The supportarm 77 is formed with a non-rectangular, non-triangular cross-section.By way of example, the support arm 77 may have a fluted cross-section toprovide channels 86 that form crimp pockets to receive crimp sleeves asexplained hereafter. The channels 86 extend along and are spaced apartfrom the termination pins 73-76. The support arm 77 is formed with achannel 86 proximate to each of the termination pins 73-76. The channels86 are separated from one another by ribs 88 that are located generallybetween adjacent termination pins 73-76 and extend in a common directionas the termination pins 73-76. FIG. 2B better illustrates thecircumferential arrangement of the termination pins 73-76 that extend ina common direction as the longitudinal axis 58. The termination pins73-76 are radially positioned outward from the longitudinal axis 58 andare spaced a select distance from one another to form a circumferentialdistribution about the lead mating end 56.

FIG. 2B also illustrates the support posts 72 to be tubular in shape andextend beyond an end 90 of the body segment 52. The support posts 72provide added lateral support for the termination pins 73-76, such asduring assembly and implant. The termination pins 73-76 are configuredto be attached to proximal ends of corresponding ones of a plurality ofconductors within the lead body 12 (as explained herein).

The core post 78 projects from the outer end of the support arm 77 andis centered along the longitudinal axis 58. The core post 78 may includeone or more flared barbs 79 that is shaped and dimensioned to befrictionally secured within a core lumen within the proximal end portion16 of the lead body 12. The barb 79 and core post 78 securer engage thedistal end portion 16 to maintain the lead body 12 in an attached mannerto the end of the connector assembly 50. The core post 78 securelyengages the proximal end portion 16 to afford stability during assemblyand afford a seal to prevent medical adhesive leakage during backfillingoperations. It is recognized that additional fixation mechanisms may beused to secure the lead body 12 to the connector assembly 50, such asadhesives and other frictional features. For example, the support posts72 may collectively define an outer envelope that is substantiallysimilar to an interior dimension of a sheath of the lead body 12 suchthat the sheath at the distal end portion 16 frictionally engages theperipheral surfaces of the support posts 72.

FIG. 2C illustrates an end view of the connector assembly 50 from thelead making end 56. As shown in FIG. 2C, the support arm 77 includes afluted cross-section having channels 86 that are positioned proximate toeach of the termination pins 73-76. The spacing between the terminationpins 73-76 and the corresponding channels 86 provide an area into whichcrimp sleeves are loaded onto the termination pins 73-76 to be coupledto the conductors within the lead body 12. Optionally, the support arm77 may be removed entirely. Optionally, the support arm 77 may beprovided with an alternative cross-section that affords sufficient spacefor the conductors to be terminated to the termination pins 73-76.

In accordance with at least one embodiment herein, a fluted geometry isprovided on the support arm 77 with four channels or troughs that arepositioned 90° from each other and off the pin axis by a select amount(e.g., 8°) to accommodate four evenly spaced distal termination pins.The troughs or channels 86 allow for placement of termination crimpsleeves within the space allowed by the interconnect region 68 (alsoreferred to as a connector boot). The 8° offset of the centers of thechannels 86 relative to a center of the termination pins 73-76 enablesthe crimp sleeves to be centered in the channels 86 to maximizeclearance between components and facilitate assembly. In addition, theribs 88 provide improved interaction with and locating of theinterconnect region 68.

FIG. 2D illustrates a sectional view taken along line 2D-2D in FIG. 2Cthrough the connector assembly 50 in accordance with an embodimentherein. The sectional view of FIG. 2D is taken through two of thetermination pins 74-75 and through a center of the support arm 77. FIG.2D illustrates the body segment 52 with the support arm 77 extendingfrom the lead mating end 56. The body segment 52 over-molds the ringcontacts 64-66, connector pin 80 and termination pins 73-76.

By way of example, the connector assembly 50 may represent an IS4 leadconnector that allows connection of four co-radial cable connectors andno inner coil conductor. In certain cardiac resynchronization therapy(CRT) leads (and other passive fixation leads), connector pin rotationis not required. To reduce manufacturing process steps and eliminateaxial pin movement (e.g., allow for the maximum allowable tolerance onlinear contact and seal zone dimensions), the connector pin 80 isover-molded into the IS4 connector. The connector pin 80 (also referredto as a center conductor) may run a length of the body segment 52 andpartially into the support arm 77 to provide structural rigidity and ameans of terminating the connector pin 80. A collar 98 is present on theconnector pin 80 distal of the connector pin to prevent the connectorpin 80 from pulling out from the molded IS4 connector body when atensile load is applied. In accordance with at least one embodiment, tomaintain structural rigidity during molding while allowing for maximummolded material thickness between the center conductor and the rings forimproved electrical isolation, a tapered center conductor design isutilized on the connector pin 80. The outer diameter of the connectorpin 80 decreases from a maximum diameter at the proximal end to aminimum diameter at the distal end.

The termination pins 74 and 75 (as well as termination pins 73 and 76)are radially outwardly spaced from the longitudinal axis 58. Theconnector pin 80 includes a base section 92 that is rigidly securedduring the molding process within the body segment 52. The connector pin80 also includes an interconnect section 94 that extends beyond theheader mating face 54 of the body segment 52. The interconnect section94 of the connector pin 80 is sized, shaped and dimensioned to besecurely received within (and conductively coupled to) a pin receptaclewithin the header 106 on the IMD 100. Additionally or alternatively, theinterconnect section 94 may be sized, shaped and dimensioned to besecurely received within (and conductively coupled to) a pin receptaclewithin an external device 600.

As illustrated in FIG. 2D, the connector pin 80 is aligned with andextends along the longitudinal axis 58 of the body segment 52. Theconnector pin 80 includes a lumen 87 that extends along the entirelength of the connector pin 80. The support arm 77 and core post 78 alsoinclude a lumen 89 that aligns with the lumen 87. The lumens 87 and 89align with a core lumen extending along a length of the lead body. Byway of example, the lumen 87, 89 and lumen of the lead body may receivea guide wire or stylet or other tool in connection with implanting orexplanting the lead. The connector pin 80 includes an inner end 94 thatis terminated within one of the support arm 77 and body segment 52. Theinner end 94 of the connector pin 80 is spaced apart from and does notphysically or electrically touch conductors within the lead body 12.Instead, the support arm 77 and core post 78 project beyond the innerend 94.

The barb feature 79 on the post 78 provides stability during assemblyand creates a seal to prevent medical adhesive leakage into the innerlumen of the lead body. The post 78 and barb feature 79 are sized to beaccepted into the inner diameter of the load body. An interference fitbetween the inner diameter of the lead body and post 78 and barb feature79 improves stability during assembly and affects a seal to preventleakage of medical adhesive to the inner diameter of the lead. In thisembodiment, a tapered “barb” feature is utilized to increase the amountof interference between components over a small region. Optionally, thebarb feature 79 may be omitted.

In the illustrated embodiment, the inner end 94 of the connector pin 80extends into the support arm 77 to provide added mechanical strength tothe support arm 77. Optionally, the inner end 94 may be terminatedwithin the body segment 52 or extend into the core post 78. The basesection 92 of the connector pin 80 may be constructed in a taperedmanner with a larger diameter proximate to the header mating face 54 anda smaller diameter proximate to the lead mating end 56. The taper in thebase section 92 may be a constant gradual taper, a series of steppedtapers or otherwise. As one example, the taper in the base section 92facilitates maintaining a fixed axial relation between the connector pin80 and the body segment 52 during insertion and connection to a header106. The flared collar 98 located within the body segment 52 facilitatesmaintaining a fixed axial relation between the connector pin 80 and thebody segment 52, such as during manufacturing, assembly, implantation,operation and otherwise. For example, during attachment of the connectorassembly 50 to a header 106, an axial loading pressure or force may beexperienced on one or both of the connector pin 80 and body segment 52.The adhesive and structural feature interconnection between theconnector pin 80 and body segment 52 prevent axial movement therebetween when exposed to axial loading or tensile (puffing) pressures andforces.

A collar coupler 150 securely and electrically couples a proximal end ofthe termination pin 74 to the ring contact 64. A collar coupler 152securely and electrically couples a proximal end of the termination pin75 to the ring contact 66. While not illustrated in FIG. 2D, separatecollar couplers securely and electrically couple the termination pins 73and 72 to the ring contact 65 and the connector pin 80.

FIG. 2E illustrates a sectional view taken along line 2E-2E in FIG. 2Cthrough the connector assembly 50 in accordance with an embodimentherein. The sectional view of FIG. 2E is taken through the twotermination pins 73, 76 that are oriented at a right angle to thetermination pins 74, 75 through the section line 2D-2D. FIG. 2Eillustrates the body segment 52 with the support arm 77. The bodysegment 52 includes the ring contacts 64-66 and connector pin 80.

In the cross-sectional view of FIG. 2E, a support collar 164 isillustrated with the base segment 166 extending about the interconnectsection 94 of the connector pin 80. The support collar 164 also includesa standoff section 168 that securely receives and retains the base stem158 of the termination pin 73. As illustrated in FIG. 2E, thetermination pin 73 represents a straight pin 10 where the base stem 158is held in the standoff section 168 a predetermined distance spacedapart from the support arm 77 to afford a gap 170 there between. Thetermination pin 76 extends a greater length than the termination pin 73such that the base stem 158 of the termination pin 76 extends to theintermediate ring contact 65. A collar 150 joins the base stem 158 ofthe termination pin 76 to the ring contact 65.

The termination pins 74 and 75 (as well as termination pins 73 and 76)are offset radially from the longitudinal axis 58. The connector pin 80includes a base section 92 that is rigidly secured during the moldingprocess within the body segment 52. The connector pin 80 also includesan interconnect section 94 that extends beyond the header mating face 54of the body segment 52. The interconnect section 94 of the connector pin80 is sized, shaped and dimensioned to be securely received within (andconductively coupled to) a pin receptacle within the header 106 on theIMD 100. Additionally or alternatively, the interconnect section 94 maybe sized, shaped and dimensioned to be securely received within (andconductively coupled to) a pin receptacle within an external device 600.

FIG. 3A illustrates a perspective view of interconnection area betweenthe connector pin 80 and the corresponding termination pin 73 inaccordance with an embodiment. The support collar 164 is configured tomaintain a secure and conductive connection between the interconnectsection 94 and the termination pin 73. The support collar 164 includes abase segment 166 and a standoff section 168 formed integral with oneanother. The base segment 166 extends about the interconnect section 94,while the standoff section 168 projects radially outward from thelongitudinal axis 58. The standoff section 158 is positioned to enclosethe base stern 158 thereby providing added mechanical support to theinterconnection between the termination pin 73 and the interconnectsection 94.

To accommodate termination of multiple (four) termination crimp sleeveand cable assemblies, an offset termination method (as illustrated inFIGS. 3A and 3B) is used to connect the fourth termination pin 74 to thecenter connector pin 80. The offset termination provides the electricalconnection from the lead connector pin 80 to the distal tip electrode.Two designs for this attachment method are illustrated, namely the“outrigger” concept (FIG. 3A) and the “bent pin” concept (FIG. 3B). Theoutrigger concept utilizes a collar-like component which is welded tothe connector pin 80. The fourth termination pin 74 is welded to theoutrigger component prior to over-molding. The bent pin concept (FIG.3B) utilizes a distal termination pin 74 that is formed with two bendsand welded directly to the center connector pin 80 prior to molding.

FIG. 3B illustrates a perspective view of an interconnection areabetween the connector pin 80 and the corresponding termination pin 73 inaccordance with an embodiment. In FIG. 3B, a portion of the interconnectsection 94 is illustrated along with a tapered step 154 betweendifferent diameter portions of the interconnect section 94. Theinterconnect section 94 also includes a recess 166 extending in thedirection of the longitudinal axis 58 and located along the perimeter ofthe interconnect section 94. The termination pin 73 includes a base stem158, an offset section 160 and a main leg 162 formed integral with oneanother and shaped, relative to one another, in a curved relation. Thebase stem 158 fits into the recess 156 to form a physical and electricalconnection between the termination pin 73 and connector body 80. Thebase stem 158 includes an outer end that abuts against a terminating endof the recess 158 to prevent and resist axial movement of thetermination pin 73 relative to the interconnect section 94, such asduring assembly with the lead body 12. The offset section 160 is curvedto extend in a generally radial direction outward from the interconnectsection 94 in a non-parallel orientation relative to the longitudinalaxis 58. As illustrated in FIG. 3B, the offset section 160 extends at anacute angle relative to the longitudinal axis 58.

Optionally, the offset section 160 may extend perpendicular or inanother direction relative to the longitudinal axis 58. The main leg 162extends at an obtuse angle relative to the offset section 160 such thatthe main leg 162 extends generally parallel (or at a very small acuteangle relative) to the longitudinal axis 58. The main leg 162 isradially displaced from the interconnect section 94 to provide a workingspace there between, as well as room for the support arm 77.

FIG. 4 illustrates a flowchart for a method of manufacture for a leadassembly in accordance with embodiments herein. The method provides alead connector, beginning at 402 by coupling a connector pin and a firsttermination pin to one another through a collar coupler such that theconnector pin and first termination pin are in an axially offsetalignment with one another. At 404, the ring contacts 64-66 are attachedto corresponding termination pins 74-77 through collar couplers 150.Optionally, also at 404, the insulated tubing sections 172 may be placedover the termination pins 74-77.

At 406, the connector pin, termination pins, ring contacts and any otherappropriate structures described herein or otherwise known are loadedinto a mold at predetermined positions relative to one anothercorresponding to the final positions and spacing to be maintained in thefinal connector assembly 50. For example, FIG. 8 illustrates thecomponents as loaded in a mold.

At 408, the material forming the body segment is injection molded whilein a liquid state, at an elevated temperature and under high pressure,such that the liquefied material fills the appropriate areas within themold and securely engages each of the other components loaded into themold. Once the body segment cools and solidifies, the connector assemblyis removed from the mold. Optionally, finishing operations may beperformed, such as (but not limited) to removing excess material fromsurfaces of the ring contacts and elsewhere.

At 410 conductors within the lead body are securely and electricallyattached to the termination pins. For example, as shown in FIG. 5,proximal ends of the conductors may be loaded into crimped sleeve thatare then loaded over the termination pins in the areas proximate thechannels along the sides of the support arm. Exterior surfaces of thecrimped elements are collapsed in a crimping manner to securely affixthe conductors and the termination pins within the crimped sleeves.

At 412, a proximal end of the lead body is attached to the lead matingend of the connector assembly. A plurality of electrodes are disposedalong the lead body, where separate conductors are joined to each of theelectrodes. For example, the lead body may include a lumen thatfrictionally receives the core post. Additionally or alternatively, theproximal end of the lead body may be secured to other features on thelead mating end of the connector assembly. When the lead body is fullyloaded onto the lead mating end of the connector assembly, the outershroud of the lead body securely abuts against the lead mating end toform a tight seal with the body segment.

FIG. 6 illustrates an end view of the connector assembly 50 from thelead mating end 56 after the crimping sleeves have been installed tosecure the conductors to the termination pins 73-76. End views ofcrimping sleeves 178 are illustrated. Each crimping sleeve 178 includesa wire reception area 182 and a pin reception area 184. The conductors186 are inserted into the wire reception area 182, while the pins 73-76are inserted into the pin reception areas 184. When the components arealigned in a desired manner, one or more deflection portions 180 locatedalong a length of each crimping sleeve 178 are crimped or deflectedinward to frictionally and securely engage the corresponding pin 73 andconductors 186.

In FIG. 6, the support arm 77 includes a fluted cross-section havingchannels 86 that are positioned proximate to each of the terminationpins 73-76. The spacing between the termination pins 73 to 76 and thecorresponding channels 86 provide an area into which crimp sleeves areloaded onto the termination pins 73-76 to be coupled to the conductorswithin the lead body 12. Optionally, the support arm 77 may be removedentirely. Optionally, the support arm 77 may be provided with analternative cross-section that affords sufficient space for theconductors to be terminated to the termination pin 73-76.

FIG. 7 illustrates a side perspective view of the lead mating end 56 ofthe connector assembly 50 and the proximal portion 190 of the lead body12. The lead body includes multiple conductors 191-194. The conductors191-194 wrap around in a spiral manner about a core lumen 195 within thelead body 12. As explained above, the core post 78 is securely affixedwithin an open end of the lumen 195 and the proximal ends of theconductors 191-194 are secured to the termination pins 73-76.

Optionally, embodiments herein may be implemented with passive or activefixation leads. For example, the connector assembly 50 may beimplemented with an active fixation lead where the connector pin 80 isnot needed to rotate to cause rotation of the fixation element. Forexample, the fixation element may be driven in other manners.

It is to be understood that the subject matter described herein is notlimited in its application to the details of construction and thearrangement of components set forth in the description herein orillustrated in the drawings hereof. The subject matter described hereinis capable of other embodiments and of being practiced or of beingcarried out in various ways. Also, it is to be understood that thephraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventionwithout departing from its scope. While the dimensions, types ofmaterials and coatings described herein are intended to define theparameters of the invention, they are by no means limiting and areexemplary embodiments. Many other embodiments will be apparent to thoseof skill in the art upon reviewing the above description. The scope ofthe invention should, therefore, be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Moreover, in the following claims, theterms “first,” “second,” and “third,” etc. are used merely as labels,and are not intended to impose numerical requirements on their objects.Further, the limitations of the following claims are not written inmeans-plus-function format and are not intended to be interpreted basedon 35 U.S.C. §112(f), unless and until such claim limitations expresslyuse the phrase “means for” followed by a statement of function void offurther structure.

What is claimed is:
 1. A method of manufacturing a lead assembly,comprising: providing a lead connector by: coupling a connector pin to afirst termination pin through a collar coupler such that the connectorpin and first termination pin are in an axially offset alignment withone another; and over molding a body segment about the connector pin,the first termination pin and the collar coupler, the body segment beingelongated along a longitudinal axis and extending between a headermating face and a lead mating end, the connector pin positioned alongthe longitudinal axis and extending from the header mating face, thefirst termination pin positioned axially offset from the longitudinalaxis and extending from the lead mating end; attaching the leadconnector to a proximal end portion of a lead body having a plurality ofelectrodes disposed along the lead body, the lead body including aplurality of cable conductors; and joining the first termination pin toa proximal end of a first conductor from the plurality of cableconductors.
 2. The method of claim 1, further comprising affixing theconnector pin within the body segment in a non-rotational manner, andelectrically coupling the connector pin to the first conductor byattaching the first conductor to the first termination pin through acrimp sleeve, the cable conductors winding in a spiral manner about alength of the lead body.
 3. The method of claim 1, further comprisingcoupling a plurality of termination pins to ring contacts; loading theplurality of termination pins, the ring contacts, the first terminationpin, and the connector pin into an injection mold; and over molding theplurality of termination pins, the ring contacts, the first terminationpin, and the connector pin such that the plurality of termination pinsproject from the lead mating end and the ring contacts extendcircumferentially about an exterior of the body segment at predeterminedpositions spaced along the body segment.
 4. The method of claim 1,further comprising spacing the ring contacts along a length of the bodysegment by a spacing relative to the header mating face of the bodysegment.
 5. The method of claim 1, wherein the plurality of terminationpins and the first termination pin extend inn common direction as thelongitudinal axis and are radially distributed outward from thelongitudinal axis in a circumferential arrangement about the lead matingend.
 6. The method of claim 1, wherein the connector pin includes a basesection that is tapered along a length thereof and is rigidly securedduring molding within the body segment.
 7. The method of claim 1,wherein the body segment includes a lead interconnect region extendingfrom the lead mating end, the lead interconnect region having a flutedcross-section to form crimp pockets, the conductors being joined throughcrimp sleeves to corresponding termination pins in the crimp pockets. 8.The method of claim 1, wherein the body segment further comprises asupport arm and core post projecting from lead mating end and centeredalong the longitudinal axis, the core post including a flared barb, thecore post and barb shaped and dimensioned to be frictionally securedwithin a core lumen within a proximal end portion of the lead body.